java-杰克逊解析JSON数组 [英] java jackson parse json array

问题描述

我需要解析方面的帮助，我尝试创建其他类型的模型类，但是没有用，请在这里帮助我. json看起来像这样:

I need help with parsing, I've tried to create a different kind of model classes, but no use, please help me out here. the json looks like this:

[
  [
    1518909300000,
    "0.08815700",
    "0.08828700",
    "0.08780000",
    "0.08792900",
    "1727.93100000",
    1518910199999,
    "152.11480375",
    5118,
    "897.71600000",
    "79.04635703",
    "0"
  ],
  [
    1518910200000,
    "0.08788400",
    "0.08824200",
    "0.08766200",
    "0.08810000",
    "1789.81300000",
    1518911099999,
    "157.20177729",
    6201,
    "898.89500000",
    "78.95697080",
    "0"
  ]
]

并且我正在尝试使用数据类来解析它:

and I'm trying to parse it using data class:

@JsonIgnoreProperties(ignoreUnknown = true)
public class KlineResponse {

    public List<Kline> getKlineList() {
        return klineList;
    }

    public List<Kline> klineList;

    public class Kline {
        @JsonProperty("4")
        Double close;

        @JsonProperty("8")
        Integer tradesNumber;

        public Double getClose() {
            return close;
        }

        public void setClose(Double close) {
            this.close = close;
        }

        public Integer getTradesNumber() {
            return tradesNumber;
        }

        public void setTradesNumber(Integer tradesNumber) {
            this.tradesNumber = tradesNumber;
        }
    }
}

和这行

mapper.readValue(response.getBody(), new TypeReference<List<KlineResponse>>(){})

或

mapper.readValue(response.getBody(), KlineResponse.class)

但是每次都会出现错误: 无法从START_ARRAY令牌中反序列化pt.settings.model.KlineResponse实例， 请帮助

but each time the error: Can not deserialize instance of pt.settings.model.KlineResponse out of START_ARRAY token, please help

推荐答案

核心问题是您收到期望的数组数组和对象数组.将mapper.readValue(response.getBody(), KlineResponse.class)更改为mapper.readValue(response.getBody(), Object[].class)即可确认.

The core issue is that you receive an array of arrays where you expect and array of objects. Changing mapper.readValue(response.getBody(), KlineResponse.class) to mapper.readValue(response.getBody(), Object[].class) confirms it.

关于如何进行操作，您有两种选择:

You have a couple of options on how to proceed:

1. 按照@ cricket_007在他的答案
上的建议，从Jackson更改为标准JSON解析.
2. 不是将其映射到对象，而是尝试以不同的方式访问JSON.有关示例，请参见@jschnasse的答案.
3. 如果可以，请更改您解析的文本格式
4. 如果您无法更改输入格式，则可以
   • 创建一个构造函数，并使用@JsonCreator对其进行注释，如指示此处
   • 将输入解析为对象数组，并将解析后的数组馈入您自己的构造函数中

1. Change from Jackson to standard JSON parsing, as suggested by @cricket_007 on his answer
2. Instead of mapping it to an object try to access the JSON differently. See @jschnasse's answer for an example.
3. Change the format of text you parse, if you can
4. If you can't change the format of the input then you can either
   • Create a constructor and annotate it with @JsonCreator, like instructed here
   • Parse the input as Object array and feed the parsed array into a constructor of your own

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